It really depends on the type of community. I created a few a missed from Reddit and honestly the screenshot/photo based communities are piss easy to start. !badrealestate for example is 3 weeks old with 48 posts and 3.6k subscribers. I just posted every day for a few weeks, now other people are posting and I contribute a couple of times a week.
On the other hand !tennis_fans and !downtherabbithole are much harder to get going because they require very regular or in depth text posts. Those two have less than 200 subscribers between them.
What I find really annoying is when people criticise posts on the communities I’ve created, when they haven’t contributed at all. People want more communities, people want more content. Don’t be a dick and then criticise the content that someone has put their time and effort into sharing with you for your enjoyment! Anyway, rant over.
If anyone’s browsing this thread and looking for more (active) communities to join, there’s also !DontYouKnowWhoIAm!clevercombacks!murderedbywords and !confidently_incorrect